"Indications are it is AQI. But that's only the initial feel right now," he said. "But it appears to be the sensational type attack of AQI character from what our assessment is right now."

At the same market last November, a bomb hidden in a box of birds exploded, killing at least 15 people and wounding dozens.

An eyewitness at the second bombing, in a predominantly Shi'ite area of the capital, said a female suicide bomber detonated explosives at a bird market.

He says a woman came to the market and said she had birds for sale, so people gathered around her and then the blast occurred.

The chief Iraqi military spokesman in Baghdad, Brig. Gen. Qassim al-Moussawi, claimed the female bombers had Down Syndrome and that the explosives were detonated by remote control, indicating the women may not having been willing attackers.

U.S. Ambassador to Iraq Ryan Crocker, speaking to the Associated Press, said the bombings show that what he called a resilient al-Qaida has "found a different, deadly way" to try to destabilize Iraq.

Militants have targeted pet markets several times since the start of the Iraq insurgency.

Friday's attacks were the deadliest in the Iraqi capital since August, when three car bombs killed more than 80 people. Female suicide bombers are being used more frequently and are believed to be part of the al-Qaida in Iraq network.